Therapeutic lamp



Aug. 14, 1928.

F. A. ANDERSON THERAPEUTIC LAMP Filed Jan. 15, 1927 Jnmszzfor 72724Afiarson i 60M, I

2Q M r 42%2 22 s.

Patented Aug. 14, 1928.

UNITED STATES PATENT OFFICE.

IFRI'IZ A. ANDERSON, OF MILTON, WISCONSIN, ASSIGNOR TO THE IBURDICKCORPORA- TION, OF MILTON, WISCONSIN, A CORPORATION F DELAWARE.

THERAPEUTIC LAMP.

Application filed January 13, 1927. Serial No. 160,802. I

My invention relates to therapeutic lamps.

It will be explained as embodied in a water-cooled lamp whereinthe-light rays are generated by a mercury are enclosed in a quartz' tubeor envelope. Water-cooled mercury arc lamps, such for example asillustrated in Fritz A. Anderson Patent No. 1,435,193, dated November 11, 1922, and F. W. Robertson, et al., Patent No. 1,568,345, datedJanuary 5, 1926, have been employed extensively, but certaindifficulties have been encountered in their use due to the formation'offilms or fogs upon the faces of the lenses through which the light rayspass.

I In order to cool the quartz lenses and the rays passing therethrough,it has been the practice, asshown in the patents heretofore ment1oned,to cause the cooling water to circulate over the faces of the rockquartz lenses 2 through which the rays are projected. Ex-

perience has shown that sooner or later the lenses become fogged orfilmed with a de-- posit which seriously interferes with the passage ofthe light rays, particularly the highly germicidal short ultra-violetrays. Thus the efficiency of the lamp maybe seriously afiected, and thegermicidal properties of the light emanating therefrom materiallylessened after a short period of use. Likewise, the establishment andrepetition of astandard or fixed technique is interfered with because ofthe variations in the quantity and quality of'the ultraviolet rayoutput. Thus, when the lenses are free from deposit, a time a ofapplication which would result in painful and possibly serious burns,would not be long enough for proper treatment, when the lenses becomefilmed after a few days or a few Weeks of service.

The principal source of this deposit is believed to be ingredientscarried by the cooling water, such as the mineral content of the waterand particles of metal, rubber and other substances washed from thepipes, tubing and other appliances associated with the cooling-watersupply. Possibly thedeposit may be accelerated by the action of thelight rays upon the water-borne ingredients. But whatever the cause maybe, it has been impossible heretofore entirely to eliminate thedifficulty, even with the use of distilled water and specially preparedtubing and metal parts in the cooling system.

One of the objects of my invention is to provide an improved therapeuticlamp.

Another object is to provide a lamp with lenses which are fluid cooled,but cannot be deleteriously fogged or filmed by the cooling fluid oringredients carried thereby.

Another object is to provide a lamp wherein the cooling fluid does notcome in contact with any lens face.

- Another object is to provide a lamp wherein the lenses are cooled bydirect contact with the cooling fluid at the edgev only.

' Another object is to provide a lamp which is strong, durable,uniformly efiicient, and

inexpensive to produce.

Other objectsand advantages will hereafter appear.-

One embodiment of the invention, incorporated in a lamp of a generallywell-known type similar to that shown in the aforesaid Anderson patent,is illustrated in the accompanying drawing, wherein f Fig. 1 is asubstantially axial section b through a complete therapeutic lampembodying my invention,

Fig. 2 is a section on the line 2-2 of Fig. 1,

Fig. 3 is a perspective of the lens holder.

The lamp chosen for illustration comprises in general a housing and amercury arc lamp or burner 5 of well known type. The housing includestwo spaced apart metal casings, an inner casing'6 and an outer casing 7The space between the casings forms a coolingfluid chamber about thelamp or burner. This cooling-fluid chamber is closed at its upper end bya top wall 8 and at its lower end by a bottom wall 9. Water is fed tothis chamber through an inlet connection 10 and is removable through anoutlet connection 11. These inlet and outlet Water connections may becoupled respectively to .any suitable source of water supply and waste.

far described is well known and is illustrated and described in detailin the aforesaid Anderson patent.

The inner casing is provided with an opening or light window 17 and theouter casing is rovided with a similar opening or light window 18. Thesewindows are in alignment so that the rays of the lamp can passtherethrough from the inside to the outside of the housing and, forconvenience in manufacture and assembly, I prefer to make them ofcircular cross section. Inner casing 6 about the rim of its window isinternally threaded to receive the complementary threaded end of a lensholder or support 19. This lens support or holder, which is shown mostclearly in Fig. 3, comprises a tubular metal shell having an annularflange 20 at its inner end and an annular flange 21 at its outer end.Inner flange 20 is externally threaded to fit the complementary threadabout the rim of the window of the inner casingas previously mentioned,and has an outwardly projecting annular shoulder 22 adapted to abut theinner casing and thereby assist in the production of a fluid tight jointtherebetween. Flange 20 is also provided with an inwardly projectingannular shoulder 23 and an annular ledge 24: against which the rear endof the lens is seated as will be hereinafter described. The forwardfiange 21 of the holder is provided with an annular ledge 25 againstwhich the forward end of the lens is seated.

The barrel of the holder between .the lenses is provided with a seriesof relatively large openings 26 so that the holder forms in effect anopen-work cage consisting of the two end flanges and the relativelysmall a zid widely separated interconnecting webs 2 The lens I considerpreferable comprises a single solid cylindrical body 30 of fused quartzwhich is inserted within the holder to rest upon ledges 24 and 25,although, of course, a hollow lens may be used. I have found that for alens diameter of about 1 the thickness should. be about to affordsuflieient edge surface to maintain the lens at a suitable temperature.To insure against leakage a packing ring 31 of fabric or other suitablematerial may be inter osed between the rear of the lens and the s oulder23. A shouldered locking ring 32 is provided to support and retain theouter end of the lens holder and to close the opening between the holderand the rim of the window of the outer casing. To the rear of itsshoulder 33 ring 32 may be externally threaded to screw into aninternally threaded flange 34 which is formed in outer casing 7 aboutthis window. After being screwed into place ring 32 and the flange ofthe outer casing may be soldered together.

To the front of shoulder 33 ring 32 is externally threaded to receive alens holding ring 35 provided with an inwardly projecting front annularflange 36. A packing ring 37 may be interposed between the lens andflange 36 so that when ring 35 is screwed into place the lens is held inits holder and water tight joints are assured. Lens retaining ring 35may serve as part of a suitable adapter, such for examp e as thatdisclosed in F. A. Anderson Patent No. 1,559,062 dated October 27, 1925.In order to prevent the parts from becoming loose and to insure againstleakage between the lens holder and locking ring 32, the adjacent frontcorners thereof may be slightly chamfered so that when they are properlypositioned a small groove 38 is provided between them. A suitable soldermay be run into this groove to effect a reliable seal and look.

In operation the water enters the coolingfluid chamber through inletconnection 10 and passes upwardly past the lens through outlet 11. Dueto the open-work or cagelike construction of the lens holder the coolingwater comes into direct contact with the lens but only about the edgethereof. And, since the lens is out of contact with the webs forming thebarrel of the holder, the water bathes substantially the entire edge ofthe lens. None of the circulating cooling water can come into contactwith either face of either lens and consequently whatever deposite mayaccumulate can have no di1atorious effect whatever upon the free passageof the light rays.

In addition to the elimination of light obstruction due to the foggingof the lens faces, the construction posseses a number of other importantadvantages. The elimination of the fogging of the faces of the lensesmakes it unnecessary to clean their inner surfaces, and in consequenceit is unnecessary to arrange for the ready removal of the lenses forcleaning purposes. Thus the lenses and holders may be non-removablyanchored in position and breakage from aecidental or deliberate removalis eliminated. Therefore proper adjustment can be made at the factoryand, when once made, need not be disturbed. Also, because it isunnecessary to remove'the lenses for 'cleaning them, they may be placedclose to the burners, the thickness of the solid lenses rendering themless easily broken by heat or shocks, and the water tight packingsremain more reliable, lessening the tendency for leakage. Theelimination of fluid pres sure against the faces of the lenses removesthe danger or breakage in the event the water pressure rises. Assemblingis facilitated because the relatively small areas of the lenses comingin contact with their seats makes variations and irregularities in thevariations both in the barrels of the holders and in the body of thelenses.

Having thus illustrated and described an embodiment of my invention,what I claim and desire to secure by United States Let-- ters Patent isas follows:

1. A therapeutic lamp housing comprising a casing for enclosing a lampand having a window therethrough for the passage of rays generated bythe lamp, a lens closing the window in the casing, and fluid connectionsfor circulating a cooling fluid about the lens against its edge only.

2. A lamp housing comprising a double walled casing, the walls havingaligned windows, means for supporting a lamp within the inner casing,connections for taking a cooling fluid to and from the space betweenthecasing Walls, a lens, and a lens support bridging the space between thecasing walls adjacent the windows, said support presenting only the edgeof the lens to the cooling fluid flowing through the space between thecasing walls.

3. A therapeutic lamp housing comprising a lamp casing having inner andouter spaced apart walls provided with aligned windows for the passageof light therefrom, an open work lens holder bridging the space betweenthe casing walls adjacent the windows, and a lens seated in the holderto close the ends thereof and thereby presenting only its edge directlyto the effect of the cooling fluid circulating through the space betweenthe casing walls and through the open work of the holder.

4. A therapeutic lamp housing comprising a lamp-containing casing formedwith two walls spaced apart to provide a chamber therebetween for theflow of a cooling fluid, the walls having aligned windows through whichthe light may be projected from a lamp within them, a tubular lenssupport framing and extending between the windows and having openingsthrough its sides, and a single solid lens carried within the holder andclosing the ends thereof whereby cooling fluid in the chamber betweenthe casing walls comes into direct contact with the edge only of thelens through the holder openwork and cools the same.

5. A therapeutic lamp housing comprising a double-walled casing forholding a lamp, the space between the walls forming a cooling-fluidcirculation chamber and the 'casing walls having aligned windows for thepassage of light, a lens, and a tubular lens holder attached to bothwalls of the casing and bridging the space therebetween adjacent thewindows, the holder having openings to permit the cooling fluid withinthe circulation chamber to come into direct contact with the edge onlyof'the lens and the lens holder and lens serving to seal the circulationchamber about the windows to prevent leakage of the cooling fluid.

6. A therapeutic lamp housing comprising a double-walled metallictubular casing for carrying a lamp, and having aligned ,windows for thepassage of rays from the lamp, the space between the casing walls Iforming a cooling-fluid circulation chamber, a tubular openwork metalliclens holder bridged between the casing walls at the windows and in thepath of the cooling fluid, and a solid quartz lens sealed within andsupported bythe holder to close the openwork thereof, and thereby causethe cooling fluid to circulate around the holder in direct contact withportions of the edge of the lens and out of contact wih the faces of thelens.

7. A therapeutic lamp housing compris ing an inner casing and an outercasing having aligned windows and separated by a space forming acooling-fluid chamber, a tubular lens holder provided with continuousledges for supporting a lens adjacent its opposite annular corners inthe windows, the ledges being interconnected by an openwork barrel whichis out of contact with the lens and permits the cooling fluid to comeinto direct contact with only the edge of the lens when the holder is inposition bridging the fluid chamber at the windows, a lens seated intheshoulder, and a retaining ring to hold the lens to its ledges.

8. A therapeutic lamp housing compris ing a casing for enclosing a lampand having a window therethrough for the passage of rays generated bythe lamp, a lens in the casing window, and fluid connections forcirculating a cooling-fluid in relation to the lens to withdraw heattherefrom through its edge only.

9. A therapeutic lamp housing comprising a casing for enclosing a lampand having a window therethrough for the passage of rays generated bythe lamp, a lens in the casing window, and fluid connections forcirculating a cooling fluid about the lens in contact only with surfacesof the lens that are inelfective in permitting rays to pass through thewindow.

10. A therapeutic lamp housing comprising a double walled casing, thewalls having aligned windows, means for supporting a lampwithin theinner casing, connectlons for taking a cooling fluid to and from thespace between the casin walls, alens for the windows, and a lens olderfor securing the lens in place with only such surfaces 10 fluidconnections communicating with the chamber between the casing walls, alens, and a ring for retainin the lens in place in the casing with onlyt e lens area that is ineffective to pass rays out of the casing beingin position for contact with the circulating cooling fluid.

In witness whereof, I hereunto subscribe my name this 11th day ofJanuary, 1927.

FRITZ A. ANDERSON.

